London is the capital and largest city of the United Kingdom, and one of the world's leading financial, cultural, and political centres. Situated on the River Thames in south-east England, it has been a major settlement for two millennia. Today London is one of the most visited cities in the world, with a diverse population and a time zone that follows Greenwich Mean Time (GMT) in winter and British Summer Time (BST) in summer. The city is home to iconic landmarks, world-class museums, and a thriving arts and business scene.

London was founded by the Romans around 47 AD as Londinium and served as the capital of Roman Britain. After a period of decline, it grew again under Anglo-Saxon and Norman rule. The city became a major port and trading hub in the medieval period and expanded greatly during the Tudor and Stuart eras. The Great Fire of 1666 destroyed much of the medieval city but led to rebuilding. The 19th and 20th centuries saw London become the heart of the British Empire and a global metropolis.

London is one of the world's leading financial centres, with the City of London and Canary Wharf hosting major banks, insurance firms, and stock exchanges. The city's economy is driven by finance, professional services, technology, tourism, and creative industries. It is a key hub for international business and investment.

London attracts millions of visitors each year. Major attractions include the British Museum, the Tower of London, Buckingham Palace, the Houses of Parliament and Big Ben, the London Eye, and the West End theatre district. The city offers diverse neighbourhoods, markets, parks, and a rich calendar of events.